This invention relates to alignment apparatus and methods for aligning a main, high power laser beam with a workpiece by the use of a low power laser beam while the main, high power beam is shuttered off from contact with the workpiece.
This invention relates particularly to alignment apparatus and methods which incorporate a periscope for maintaining the axes of the two beams parallel while displacing the second beam laterally to be coaxial with the axis of the first beam when the high power beam is shuttered off from the workpiece.
In systems using high power laser beams to perform work on workpieces, it is desirable to have a low power beam which can be used for aligning the high power laser beam with respect to the workpiece, or for aligning the workpiece with respect to the laser beam, when the high power beam is shuttered off.
Sliding and pivoting shutter mechanisms have been used for this purpose. These mechanisms have presented a number of problems.
One problem was that the mechanisms had to be controlled very precisely. Precise control was required to insure that there would not be any wobble or changes of position of the mechanisms or any mechanical or thermal vibrations of the mechanisms which could change or affect the required coaxial positions of the two beams.
Obtaining the required precision often required the use of expensive, precision components and shutter mechanisms and robust and relatively expensive bearing mounts. Wear or other changes to the mechanisms could also introduce errors in alignment.